Numbness and pain on one entire side of the body seems like a serious symptom. It would be advisable to consult a doctor immediately to have an MRI and CT scan done. You have not mentioned whether the pain is only on the head or the entire side of your body, so this symptom could be a result of several conditions. Symptoms like numbness on one side of the body, weakness of the face, arm, and leg, trouble with articulation, understanding, sudden confusion, temporary visual impairment, dizziness, loss of balance or coordination, and sudden severe headaches could be warning signs of a stroke, and require urgent medical attention.
The symptoms could also indicate simple problems with posture when you stand, sit or sleep. The failure of blood to circulate properly within the body can cause numbness especially if the nerves are pinched. Sitting or standing for long periods of time may hinder the flow of blood to various parts of the body and this may cause a deadening of the nerve endings in the extremities. This numbness is only temporary and should go off with a change in posture. If your head rolls towards your side while sleeping and if you have placed your arm under the head while resting, you may experience numbness which should go off in 15-20 minutes. If you are a smoker, the habit can affect the circulation of blood and cause the numbness as well. Light exercises will help ease up the body, although this is no excuse to not quit smoking.
If the other symptoms are absent, you could be suffering from acute migraines which cause numbness on the face, tongue, and other extremities. Severe headaches, dizziness, and problems with vision are a few symptoms of the condition for which you may consult a doctor for a diagnosis. In the meantime you may consume a diet that is rich in green leafy vegetables, tomatoes and whole wheat to ward off attacks. Grape juice consumed several times a day is also known to help. Garlic either raw or cooked is another useful ingredient to your diet. Food rich in Vitamin C with bioflavonoid is an essential part of your daily diet as it can prevent numbness and headaches that are related to cardiovascular problems. Primrose oil possesses anti-inflammatory properties which will prevent the blood vessels from being pinched further and can be massaged onto the head. Avoid going out in direct sunlight and lie down in a dark quiet room and sleep off the headache if you do develop a migraine.